For those of you that have never played Guitar Hero III Mobile, Guitar Hero III: Backstage Pass Mobile or Guitar Hero World Tour Mobile, it might come as a shock that you can play the game without a plastic guitar (or plastic drums). Developer Hands-On got their heads around that early on in GHIII's development and were able to keep it sexy by dropping the fret count from five to three. They also were able to hang on to original song content and score master tracks by approaching music rights holders on their own, instead of waiting around for Activision to do it.

"Most of the R&D went into making the audio sound as good as possible," said Lechleiter. They got around the challenges of only having a single audio channel on most cell phones by having a third party develop an audio mixer that could supply four channels for separate sounds (guitar, drums, crowd noises, etc.), and by focusing on all the different audio types that mobile phones support (MP3, AMR, AAC, MIDI, etc.).

"Everyone wants MPS3 quality," he said. "MIDI I think is acceptable as a lowest common denominator – but that's what people are looking for, the true experience"

The game's quality isn't just about sound, though. By introducing head-to-head multiplayer that works across all different kinds of cell phone, World Tour is like a breakthrough for mobile gaming. Players can either do drums or guitar and the server does the rest in terms of matchmaking and providing four common songs between competitors. Hands-On provides a website where people can look at their stats and the stats of competitors, and the developer makes a habit of releasing one new song a month for free.

This puts their three mobile titles at something like 4 million purchases with other over 250,000 songs downloaded a day, says Lechleiter.

I think World Tour is an example of a mobile developer being aware of a platform's limits instead of blithely assuming quality doesn't matter. Hopefully, other developers will follow their lead.

"We're kind of in the infancy of music games right now," Lechleiter said. "I'm happy with [World Tour] and I'm excited to see what people can do [in the future]."

Playing virtual guitar has gotten easier with a reduction from five keys on the console game's peripheral guitar to three on the phone. Users can choose whichever keypad row feels best.

This game has a lot going for it—easy fretting, satisfying animation, and killer sound quality. Guitar Hero Mobile uses PMD audio for the BREW platform, which preserves the melody, harmony, vocals, and cacophonous ding every time you miss.